Rotary engine.



No. 732,671. ,y

T. M. ANDREWS.

ROTARY ENGINE. APPLICATION FILED DEO. 26, 1901.

PTBNTED JUNE 3 0, 1903.

No. 732,671. E Y lPAI'EN'IED JUNE 30, 1903.

T. M. ANDREWS.

" ROTARY ENGINE.

APPLICATION FILED 1330.26, 1901. No MODEL. a SHEETS-SHEET z.

PATENTED JUNE 30,*10103.

T. M. ANDREWS. ROTARY ENGINE. APPLIGATIQN FILED 02.0.20, 1901.

3 SHEETS-SHEET 3.

N0 MODEL.

Patented une SO, 1909:;

UNITED STATES PATENT OFFICE.

THOMAS M. ANDREWS, NASHVILLE, TENNESSEE, ASSlGNOR-OF ONE- FOURTH TO JOHN A. GAINES AND WORCESTER A. BRYAN, OF NASH- VILLE, TENNESSEE.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 732,671, dated June 30, 1903.'

Application iiled December 26, 1901. Serial No. 87,264. (No model.)

To all whom t may concern.:

Be it known that l, THOMAS M. ANDREWS, acitizen of the United States, residing at Nashville, in the county of Davidson, State of Tennessee, have invented certain new and useful Improvements iu Rotary Engines, of which the following is a description, reference being had to the accompanying drawings and to the characters of reference marked thereon.

My invention relates to steam-engines of the rotary type; and it is the object of my invention to simplify the construction of such engines, to construct an engine in which the steam shall be used to thefullest advantage possible, to obviate the knocking common in engines of this type caused by the impact of the steam upon the wing-piston, and to reduce the friction and leakage of steam as much as possible.

With these objects in View my invention consists in the construction hereinafter described and claimed.

Referring to the drawings, Figure 1 is a vertical cross-sectional view of an engine embodying my invention on a plane at right angles with the axis of the shaft. Fig. 2 is a vertical cross-sectional View on a plane parallel with the axis of the shaft. Fig. 3 isa plan View of the packing-disk. Fig. 4 is a View, partly in section, of one of the pistonwings. Fig. 5 is an end View of one ofthe piston-wings. Fig. 6 is a detail View showing a portion of the piston-disk in cross-section, and Figs. 7 and 8 are respectivelya plan and a cross-sectional view of one of th`eheads of the casing.

,"In the drawings, 1 is a cylindrical casing having heads 2. A power-shaft 3 is carried in bearings 4, arranged above the center of the heads 2. Within the casing, secured to the power-shaft and concentric therewith, is a piston-disk 5, having oppositely-extended openings 6, in which are carried piston-wings 7 and 8. The piston-disk 5is of such diameter and the bearings 4are so located relative to the center of the casing that at one point, preferably at the point directly above the center of the casing, the piston-disk is in contact with the inner periphery of the casing. The openin gs 6, in which the piston-wings are carried, are arranged diametricall y opposite each other. vIn the face of vthe piston-disk are formed the oppositely located eccentric grooves 9 and 10. These grooves are so located that they have their greatest depth at points ilninediatelybetween the openings 6 and taper-in both directions from these points.

The wings 7 and 8 are each provided, preferably on each side near their inner ends, with pins 11, which carry curved guides 12, which travel in grooves 13, formed in the inner faces of the heads 2, concentric with the inner periphery of the casing, but eccentric to the bearings 4.

The inner ends'ol' the piston-wings` 7 and 8 are preferably V-shaped, 'as shown in Figs. 2 and 4, andthe inner ends of the openings 6 are formed with a central rib 14, which lits this V-shaped groove, and thus prevents the piston-wings from possible lateral movement when the piston-disk is in contact with the 'inner periphery of the casing, and thus tends to lessen the friction between the disks 2'4 and the walls of the casing at this point.

The outer ends of they piston-wings 7 and 8 travel in contact with the inner periphery of the casing and for the purpose of making-a tight joint are preferably providedy with packing 15, pressed outward by ak spring 17, preferably carried` in a recess 18 in a seat-piece 19. The end walls 20 of this recess prevent lateral movement of the spring. The side edges of the piston-wings are preferably also provided with packing 21, carried in grooves 22, and preferably pressed outward against the inner faces of the heads 2 by springs 23.-

From the above description it will be seen that the piston-wings in the rotation of the shaft and thepiston-disk are always in contact with the inner periphery of the casing.

On each face of the piston-disk 5 and concentric therewith is preferably arranged a disk 24,having slots 25 therein,through which the pins 11 of the piston-wings extend to conneet with the guides 12 in the grooves 13. These disks each fit into a circular recess 26, formed in the inner face of each of the heads 2. At the periphery of these recesses is provided a groove 27, in which is placed packing 28. By this construction the'possibility of leakage of steam at the bearings 4 is obviated without the necessity for packing at these bearings.

At the point at which the periphery of the pistou-disk is in direct contact with the inner periphery of the casing I provide packing 29,

lpreferably pressed by springs 30 into close contact with the periphery of the piston-disk, and at this point I also provide a valve-carrier 3l, having its inner end adapted to tit the eccentric grooves 9 and 10. This end of the valve-carrier is preferably provided with packing 32 in order to insure a tight joint with these grooves.

The valve-chamber 33 is preferably formed in one piece with the casing l. Connected with it is the steam-inlet 34 and the exhaustopenings 35 and 3G. The steam-inlet 34 eX- tends downward into the valve-chamber and has at its lower end a valve-seat 37, adapted to receive the valve 3S, carried by the valvecarrier 3l.

From the valve-chamber 33 steam-inlets 39 and 40 extend to the interior of the casing, and each of these inlets is adapted, by means of connections 4l and 42, to act, as hereinafter described, as exhaust-outlets.

Communicating with the valve-chamber 33 are also exhaust-outlets 43l and 44, formed in the walls of the casing and opening into the casing at diametrically opposite points equally dist-ant from the point at which the 'valve-carrier 3l is located.

A valve-rod 45, operated by any convenient means, preferably by a lever 46, carries within the valve-chamber 33 valves 47 and 48,each provided with a way 49 and each adapted when in one position to open the exhaustoutlet 43 or 44 and to connect the inlet 39 or 40 with the exhaust and at the same time close the inlet 39 or 40 and when shifted in position to close the exhaust-outlet and to open the inlet 39 or 40. In the position in which the Valves 47 and 48 are shown in Fig. l the valve 47 has opened the outlet 43, and also by means of the way 49 and the connection 4l has connected the inlet 39 with the exhaust and the valve 48 has closed the eX- haust 44 and has opened the inlet 40.

The parts being in the position shown in Fig. 1, the valve-carrier resting at the bottom of the groove at its greatest depth and the valve 3S being at a distance from it-s seat, steam enters the casing through the inlet 4() and entering the groove 9 acts to force the piston-wing 7 downward, escape of steam in the opposite direction being prevented by the valve-carrier3l. As soon as the piston-disk is rotated sufficiently to carry the piston-wing 8 past the opening of the outlet 43 there will be no resistance within the casing to the further tnovementof the piston-wing 7,anysteam which fails to escape before the piston-wing S passes the opening of the outlet 43 having free exit through the inlet 39, connection 4l, and way 49. As the piston-disk continues to rotate the valve-carrier 31 will be gradually ton-wing 8.

'raised, cutting off the supply of steam.

When the piston-wing 7 has reached about the point marked a, in Fig. l, the valve-carrier will vbe raised to its fullest extent, completely shutting off the steam. From this point the steam already introduced in rear of the piston-wing 7 acts by its expansion to drive the piston-Wing 7 forward to the point marked b. The piston-wing Shaving passed the mouth of the exhaust-outlet 43, there will be no back pressure on the piston-wing 7. As the piston-disk continues to rotate the piston-wing 8 approaches the highest point of the interior periphery of the casing, the valve-carrier being still raised,' holding the valve 3S against its seat, and thus preventing the entrance of steam to the valve-chamber. As the piston-wing 7 reaches about the point marked b in Fig. 1 the piston-wing S having passed the valve-carrierand the valvecarrier having entered the groove l0, permitting the valve 38 to be forced away from its seat, steam enters in rear of the pistonwing 8. At the instant steatn enters and until the piston-wing 7 reaches the opening of the exhaust-outlet the pressure of the steam on the rear face of the piston-wing 8 is to a slight extent resisted by back pressure of the steam confined between the rear face of the piston-wing 7 and the front face of the pis- At the moment steam enters in rear of the piston-wing S the area presented by it between the periphery of the pistondisk and the inner face of the periphery of the casing is about one-fourth the area presented by the rear face of the piston-wing 7. Consequently the back pressure on the piston-wing 8 will be sufcient only to have a cushioning effect to prevent the shock or jar which might otherwise occur from the entrance of the steam, this shock or jar being, however, very slight by reason of the gradual entrance of steam due to the gradual opening of the steam-inlet. It will thus be seen that the steam is introduced gradually and cut ott gradualiy, and during a considerable portion of the rotation of the piston-disk the steam acts by its expansion, so that the full force ofthe steam is utilized.

The valve-carrier 3l is held down in contact with the grooves 9 and 10 by the pressure of the'steam and is lifted against this pressure by the rotation of the piston-disk, automatically cutting ed the steam at points determined by the grooves.

It will be understood that the curve of the bottom of the grooves 9 and lO may be varied to effect the cutting off of the steam at the points found most desirable.

I have described the operation of the engine when the valves 47 and 48 are in the position shown in Fig. 1. \Vith the valves in this position the exhaust-outlet 44 is closed and has no other function than that of affording additional space to hold steam. 3y shifting the `valves 47 and 48 by means of the lever 4U the engine will be reversed, steam entering IOO IOS

through the inlet 39 and the exhaust-outlet 44 being op'en for the escape of the steam after it has done its Work.

It will be understood that I do not limit my invention to the precise construction shown, as many changes in specific construction may be made without departing from the spirit of theinvention. Forinstance, the valve-chamber and the steam-inlets may be arranged at the bottom or the side instead of the top of the casing, so long as the relative position of the inlets and exhaust-openings are preserved, and any known form of valve may be substituted for the sliding valves shown.

The difficulty of starting the engine, due to the fact that so long as the valve 38 is held in close position no steam can be admitted to act upon the piston-Wings, may be readily obviated by coupling two engines of the construction shown on the same shaft with the piston-wings of one engine at such an angle with the piston-wings of the other that one or the other of the engines will always be in position to admit steam to act on its pistonwings. In a single engine this difficulty may be obviated by connecting the steam-chamber, by means or" suitable connections, with one of the exhaust-outlets 43 or 44, so that steam may by means of these connections be admitted directly to the steam-space in the casing.

The valve-carrier 3l' is shown square in cross-section; but it will be obvious that it may be made of any form in cross-section desired.

It will be obvious that instead of steam' any other gaseous motive iiuid may be used.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. A rotary engine comprising a casing having an exhaust-port communicating with the vinterior of the casing at a point on about the 4level of the center of the casing, and having ton-Wings, a valve-chamber connected with.

the casing by an inlet-port, an exhaust-port opening from the casing, means for admitting steam to the valve-chamber and a cut-oft` valve operated directly by the piston-disk for automatically cutting od the supply of steam to the valve-chamber before the piston-disk has completed a half-rotation; substantially as described.

3. A rotary engine comprising a casing having an exhaust-port communicating with the interior of the casing at a point on about the ievel'of the center of the casing and having antinlet-port in its upper portion, a pistondisk eccentrically mounted in the casing and y carrying oppositelyarranged piston Wings, Lmeans for maintaining the outer ends of the piston-Wings in contactk with the inner periphery of the casing, a cut-oft valve and means for operating it directly by the pistondisk; substantially as described.

4. A rotary engine comprising a casing, a

positely-arranged piston-wings and having a cam-groove in its periphery, a-valve-cham-y .piston-disk rotating therein carrying two opber connected with the casingby an inlet-f port, an exhaust-port opening from the cas-V ing, means for admitting steam to the valvechamber and means operated, by the camchamber before the piston-disk has completed a half-rotation; substantially as described;

5. A rotary enginecomprising'a casing hav- :ing an exhaust-port commnnlcating with the interior of the casing at a point on about the a cut-0E valve operated directly by the camgroove of the piston-disk for automatically cutting oft the supply of steam to the valvegroove of the piston-disk;'substantially as f described.

6. Arotary engine comprising a casing having an exhaust-port communicating with the interior of the casing at a point on about theV level of the center of the casing and having IOO an inlet-port in its upper portionpa piston- 4 disk eccentrically mounted in the casing and carrying oppositely arranged piston wings and having cam-grooves in its periphery, means for maintaining the outer ends of the piston-Wings in contact with the inner periphery of the casing, and a cut-off valve operated directly by the cam-grooves of the .piston-disk; substantially as described.v

7. Arotaryenginecomprisingacasing having an exhaust-port communicating with the interior of the casing at a point on about the level of the center of the casing, a valvechamber connected with the casing by an inlet-opening, an inlet for admitting steam to the valve-chamber, a piston-disk eccentrically mounted in the casing and carrying oppositely arranged piston wings, a cutoff valve-arranged in line with the inlet for admitting steam to the valve-chamber and operating against the force of the steam, and means for operating the valve directly by the piston-disk; substantially as described.

' 8. Arotary engine comprising acasinghaving an exhaust-port communicating with the interior of the casing at a point on about the level of the center of the casing, a valvechamber connected with the casing by an inlet-opening into the casing at its upper portion, an inlet admitting steam to the valvechamber, a piston-disk eccentrically mounted in the casing and carrying oppositely-arranged piston-wings, means for maintaining IIC) the outer ends of the piston-wings in contact with the inner periphery of the casing, a cutoff valve arranged in line with the inlet for admitting steam to the valve-chamber and operating against the force of the steam, and means for operating' the valve directly by the piston-disk; substantially as described.

9. A rotary engine, comprisinga casing, an inlet for admitting steam to the casing, an eX- haust-port and a piston-disk carrying oppositely-arranged piston-wings, the inner ends of the piston-wings being made V-shaped and the piston-disk being provided with a rib to fit the V-shaped inner ends of the pistonwings whereby the piston-wings are centered when in contact with the rib; substantially as described.

10. A rotary engine, comprising a casing having heads provided with a circular recess formed therein, an inlet for admitting steam to the casing, an'eXhaust-port, a piston-disk arranged within the casing and carrying oppositely-arranged piston-wings and radiallyslotted disks fitting the recess formed in the heads and arranged between the piston-disk and the heads, the piston-wings being provided with pins extending through the slots of the disks; substantially as described.

1l. A rotary engine, comprising a casing having heads provided with a circular recess formed therein, having at its peripherya recess for packing, an inlet for admitting steam to the casing, an exhaust-port, a piston-disk arranged within the casing and carrying oppositely-arranged piston-wings, and radiallyslotted disks iitting the recesses formed in the heads and arranged between the pistondisk and the heads, piston-wings being provided with pins extending through the slots of the disks; substantially as described.

l2. A rotary engine, comprising a casing and casing-heads, the latter having annular grooves eccentrically disposed to the move ment of the piston-disk, a piston-disk revolubly carried in the casing, having a series of radial pockets, with tapered seat portions, a series of piston-wings movable in said pockets having cut-out portions adapted to the tapered seat portions of the pockets and provided With studded projections carrying rollers movable in the aforesaid grooves for shifting the wings, as and for the purpose described. v

13. In a device of the class described, a rotary piston-disk having a series of tapered body portions, wings slidable in Ways of said piston-disk and provided with seat portions adapted to the tapered body portions of the piston-disk, and the said wings having their bodies recessed and packed with suitable packing, substantially for the purpose described.

In testimony whereof I ax my signature in presence of two witnesses.

THOS. M. ANDREWS. Witnesses:

FRANK D. BLAcKIsToNE, A. P. GREELEY. 

